Kathmandu, June 26: Its deviation from the specified route in Kathmandu’s sky led to the crash of Lufthansa Cargo at Talkhu Dondechour in the south west of Capital Valley on July 7 last year, a report, prepared by the commission to investigate the accident, said here today. All five crew-members of the ill-fated aircraft had died on the spot.

Flight DLH 8533, after it took off south from the Tribhuvan International Airport that day, made a right turn for Dharke 1A Standard Instrument Departure (meaning, the departure was based on instruments and not on the pilot’s visibility). Dharke 1A is an imaginary point in the sky for international aircraft flying to the south-west above Bharatpur, Bhairahawa, before entering the Indian aerospace.

For Dharke 1A departure, any aircraft has to reach, what aviation experts say, 270 radial in the west, four nautical miles away from TIA and an altitude of 7,500 feet. Aircraft unable to maintain that altitude are supposed to make Dharke IB departure which requires them to make a full circle of Kathmandu Valley’s aerospace — to gain height — before exiting out of its mountain rim.

The problem with the Lufthansa’s cargo airliner was that it did not take the adequate right turn to reach the 270 radial in the west for the Dharke 1A departure. Even before it could reach that point, the aircraft took a straight course brewing trouble for itself. “After climbing right turn, the aircraft then rolled out on a heading between 253 degree – 260 degree magnetic and leveled off momentarily,” read the report presented to Tarini Dutta Chataut, Minister for Culture, Tourism and Civil Aviation here today.

No sooner the aircraft reached 4.4 DME (Distance Measurement Equipment) crossing 247 degree radial, the Ground Proximity Warning System (GPWS) in the aircraft sounded “Terrain Terrain Whoop Whoop Pull Up Pull Up”, the report of the commission, headed by Narendra Kumar Shrestha, Deputy Attorney General, said. GPWS warns pilots if the flying aircraft is nearing to hit the ground.

But the pilot could not pull the aircraft up as fast as it was needed since the speed of the aircraft was already dropping. The result: The aircraft, descending at a speed of 250 feet per minute, hit the ground with full power killing all five crewmen. The total flight time of Flight DLH 8533 was three minutes 35 seconds.

The commission’s report singled out different factors for the accident including incomplete departure briefing, the unexpected airspeed decay during the initial right climbing turn, inadequate intra cockpit crew coordination and communication, and the incorrect and slow response to the initial and subsequent GPWS activation prior to the collision with the terrain.

The report has also pointed its finger at the Air Traffic Controller at the TIA. “No advisory alert was given by the Approach Controller to the crew when the aircraft deviated from the Standard Instrument Departure.” It has also made many safety recommendations for flight safety.